Patent GB-668316-A (GB)
Title: Improvements in or relating to statistical machines
Inventor: THOMAS ARTHUR
IPC: G06K7/02
Filed: 1949-05-20
Abstract: 668,316. Statistical apparatus. POWERSSAMAS ACCOUNTING MACHINES, Ltd. MAy 10, 1950 [May 20, 1949], No. 13580/49, Class 106 (i). For sensing perforations in a perforated statistical record card, apparatus comprising a sensing chamber provided with a through passage for each card index position to be sensed, means to apply negative pressure simultaneously and independently to each passage, a top plate and a bottom plate between which a card is located for sensing, the said plates each having apertures aligned with the through passages in the sensing chamber and being mounted for movement relative one to the other so that they are spaced apart to permit the movement of a card into and out of sensing relation therewith, the card being compressed therebetween during sensing, and positively moved thereby away from the sensing chamber to overcome the action of residue negative pressure, a reciprocal carriage to move said plates to and from sealing engagement with the sensing chamber. Operating means for said carriage, and a slide valve interposed between the sensing chamber and said negative pressure applying means and operable in timed relation with the operating means simultaneously to expose or close the through passages to negative pressure. Pneumatic sensing apparatus for a record card controlled statistical machine comprises a sensing chamber 24, Fig. 3, having an upper plate 25 and a lower plate 26 both perforated at each index position on a card with individual pneumatic (suction) conduits 86 to each perforation. The plates are arranged to move apart to admit a card and close together to compress the card during reading. A slide valve 78 is also provided and moves in timed relation with the machine cycle by the action of a cam and lever driven from the main shaft, to apply the negative pressure for reading at a predetermined point in the machine cycle. The presence of a card in the card chamber 24 is detected by a detector pin 48, and a card stop 66 is provided to locate the card in its correct position. In Fig. 4 one of the latch operating chambers 89 associated with each conduit 86 is shown in section, the chambers being arranged in columns corresponding to the index positions in vertical columns of the card. A flexible diaphragm 91 is housed in each chamber 89 and has its edges clamped in a housing 92. A latch 93 is pivoted at 94 to the housing 92 and is biased by a spring 95. The latch is also connected with the diaphragm 91 by a link 96, the arrange - ment being such that when normal negative pressure is applied to the diaphragm the latter is in the reverse position from that shown in section in Fig. 4, and the latch 93 is retained in inoperative position by the diaphragm against the action of the spring 95. A bar 97 carrying 12 catches 101 is mounted above the latch chambers and is reciprocated during the machine cycle to operate Bowden wires 104 where a catch has been tripped by movement of a diaphragm in response to the presence of a hole in the card, as shown in section in Fig. 4. The Bowden cables may be employed to operate a punching unit or other function in a statistical machine. Specifications 490,358 and 580,865 are referred to.